IEC 61508-7:2010

Overview

IEC 61508-7:2010 is the seventh part of the IEC 61508 series, an internationally recognized standard focusing on the functional safety of electrical, electronic, and programmable electronic (E/E/PE) safety-related systems. This document provides a comprehensive overview of the various safety techniques and measures applicable to E/E/PE systems to ensure safety functions are performed reliably, minimizing risks associated with random hardware failures, systematic failures, and software safety.

Serving as a vital resource within the IEC 61508 series, Part 7 offers a technical revision and fundamental insights into best practices and approaches to managing functional safety. It supports manufacturers, safety engineers, and industry professionals by consolidating knowledge on practical safety methods essential for meeting stringent safety integrity levels (SILs).

Key Topics

• Techniques for Controlling Random Hardware Failures
  Detailed guidance on detecting and mitigating random hardware faults in electrical and electronic components. This includes fault detection, diagnostics, redundancy, and safe failure strategies aligned with IEC 61508-2 requirements.

• Avoidance of Systematic Failures
  Strategies and measures to prevent systematic faults in both hardware and software are outlined, with references to IEC 61508-2 and IEC 61508-3. These include process controls, management of development lifecycle activities, and verification methods.

• Software Safety Integrity
  In-depth coverage of software development techniques to achieve required safety integrity levels, including programming language recommendations, validation, and verification processes based on IEC 61508-3.

• Probabilistic Approaches for Software Safety
  Explanation of probabilistic modeling techniques to assess software safety integrity, particularly for pre-developed or third-party software components, aiding risk-based decision-making for preexisting software.

• ASIC Design Safety
  Specific guidance on design measures for Application-Specific Integrated Circuits (ASICs) to reduce safety risks and meet safety integrity targets.

• Software Lifecycle Phase Properties
  Definitions and best practices for different software lifecycle phases such as design, testing, integration, and maintenance, facilitating consistent safety assurance activities.

• Object-Oriented Software Development
  Recommendations for safety-related software developed with object-oriented methods, ensuring compatibility with IEC 61508 safety objectives.

Practical Applications

IEC 61508-7:2010 finds critical application across industries where E/E/PE safety-related systems play an essential role, including:

• Smart Grid Systems
  Ensuring reliable and safe operation of smart electrical grids by applying robust safety techniques that prevent failures within control, automation, and protection systems.

• Industrial Automation
  Implementation of functional safety measures in process control and machinery automation to prevent hazards related to system failures.

• Automotive and Transportation
  Supporting safety-critical electronic systems such as braking and steering controls through reliable safety lifecycle processes.

• Energy and Power Generation
  Enhancing system safety in power plants by adhering to structured safety measures to mitigate random and systematic failures.

• Medical Devices
  Assuring safety integrity in electronic systems controlling life-supporting and diagnostic equipment.

The standard facilitates a risk-based approach to defining safety integrity requirements, enabling organizations to tailor safety strategies to specific applications and hazards. It promotes standardized safety lifecycle processes that improve consistency, safety outcomes, and cost-effectiveness across sectors.

Related Standards

IEC 61508-7:2010 complements other parts of the IEC 61508 series, which collectively address the full spectrum of functional safety for E/E/PE systems:

• IEC 61508-1: General requirements and definitions for functional safety.
• IEC 61508-2: Requirements for hardware safety.
• IEC 61508-3: Software safety requirements.
• IEC 61508-4 to IEC 61508-6: Additional guidelines for various safety aspects.

Furthermore, IEC 61508 serves as the foundation for numerous product- and sector-specific safety standards, including:

• IEC 62061: Safety of machinery using electrical control systems.
• IEC 61511: Safety instrumented systems for the process industry sector.
• ISO 13849: Safety-related parts of control systems.

These standards build upon the principles and techniques outlined in IEC 61508-7 to address specific industry requirements while maintaining consistency with global best practices in functional safety.

Keywords: IEC 61508-7, functional safety, electrical/electronic/programmable electronic systems, safety-related systems, safety techniques, safety measures, safety integrity levels, fault avoidance, software safety integrity, systematic failure avoidance, random hardware failures, smart grid safety, safety lifecycle, IEC standards.